A medium temperature curing high temperature resistant low dielectric cyanate resin system and a preparation method thereof
By introducing specific silicone resins and catalysts into cyanate ester resins, the problems of high-temperature curing and dielectric properties were solved, resulting in cyanate ester resins with low dielectric properties that can be cured at medium temperatures and are suitable for various processes.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHANGHAI SPACE PRECISION MACHINERY RES INST
- Filing Date
- 2026-03-03
- Publication Date
- 2026-06-02
AI Technical Summary
Existing cyanate ester resins have high curing temperatures, large residual stress, and modifiers that affect dielectric properties, making it difficult to meet process requirements.
Silicone resin containing structural units is used as a modifying component, combined with a specific catalyst and curing agent, and the toughness and dielectric properties of the resin are improved through a medium-temperature curing process, avoiding the use of epoxy resin.
A cyanate ester resin with low dielectric properties under medium temperature curing has been developed, which reduces energy consumption, decreases residual stress, and is suitable for a variety of process applications.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of polymer materials and preparation, and relates to a medium-temperature curing low-dielectric cyanate resin system and its preparation method. Background Technology
[0002] Cyanate ester resins were synthesized and characterized in the 1960s. Due to the unique triazine ring structure of their cured products, they possess characteristics such as high temperature resistance, low dielectric constant, and low moisture absorption. Furthermore, they can be adapted to various processes including autoclave filling, winding, and vacuum infusion, making them a class of thermosetting resins with significant application prospects. The development of cyanate esters in China has been rapid. Since the beginning of this century, thanks to continuous breakthroughs in cyanate ester monomer synthesis technology, cyanate esters have gradually evolved from high-end products towards multifunctional, mass-produced applications.
[0003] Without a catalyst, the peak temperature of cyanate ester curing exceeds 250°C, typically requiring high temperature and long curing time for complete curing. The cured material exhibits significant residual stress, severely limiting its application. Introducing catalysts and modifiers can lower the activation energy and promote tricyclization. However, currently developed catalytic systems still struggle to meet process requirements, resulting in persistently high post-curing temperatures. Chinese patent application CN117165078A discloses a cyanate ester resin with low dielectric loss suitable for filament winding processes, achieving superior dielectric properties, but with a high curing temperature. Furthermore, even if the curing temperature is lowered, modifiers such as epoxy resin added to the system can affect the system's temperature resistance and dielectric properties. CN116790121A discloses a low-temperature curable cyanate ester resin modification system and its preparation method, achieving low-temperature curing of cyanate ester; however, the addition of modifiers negatively impacts dielectric properties.
[0004] CN 114149684 A discloses a low-temperature curing, low-dielectric, high-toughness cyanate ester resin and its preparation method. Without altering the existing mature cyanate ester resin system, it introduces maleimide-based phenol containing double bonds and phenolic hydroxyl groups, allowing for curing not only at medium- and high-temperature conditions but also at low-temperature conditions below 130°C for rapid curing. Although the invention states that "the purpose of this invention is to utilize maleimide-based phenol, which has good mechanical, electrical, and heat resistance properties," this structure, as a small-molecule organic compound, offers limited improvement to the mechanical and heat resistance properties of the cyanate ester resin system, even if it does improve them. Furthermore, the phenolic hydroxyl groups of phenol still play a major catalytic curing role, representing the catalytic curing effect of phenolic substances (active hydrogen compounds) on cyanate esters. Moreover, the invention uses epoxy resin as a modifying component; epoxy resins typically have poor dielectric properties, which can negatively impact the dielectric properties of the resin system. Summary of the Invention
[0005] To address the shortcomings of the prior art, this invention provides a medium-temperature curing low-dielectric cyanate ester resin system and its preparation method, solving the problems of poor processability of existing high-performance cyanate esters and the impact of existing processes on the performance of cyanate esters, thus combining processability and functionality.
[0006] The objective of this invention is achieved through the following technical solutions:
[0007] This invention provides a medium-temperature curing low-dielectric cyanate ester resin system, wherein the cyanate ester resin system comprises 95-99 parts by weight of a cyanate ester resin matrix, 1-5 parts by weight of a curing agent, 0.01-0.1 parts by weight of a catalyst, and 5-10 parts by weight of a modifying component; the modifying component contains structural units: Silicone resin.
[0008] As one embodiment of the present invention, the cyanate resin matrix is one or a mixture of several of bisphenol A cyanate, bisphenol E cyanate, bisphenol M cyanate, and tetramethylbisphenol F cyanate.
[0009] In one embodiment of the present invention, the curing agent is an alkyl-substituted phenol.
[0010] As one embodiment of the present invention, the alkyl-substituted phenol is selected from one or more of nonylphenol, 6-ethyl-2-naphthol, guaiacol, cashew phenol, and diallyl bisphenol A.
[0011] As one embodiment of the present invention, the catalyst is one or more of tin catalyst, zinc catalyst, iron catalyst, and nickel catalyst.
[0012] As one embodiment of the present invention, the tin catalyst is one or more of dibutyltin dilaurate, tin 2-ethylhexanoate, and dioctyltin oxide.
[0013] As one embodiment of the present invention, the zinc catalyst is one or more of zinc acetylacetonate, zinc octanoate, zinc isooctanoate, zinc 2-ethylhexanoate, and zinc chloride.
[0014] As one embodiment of the present invention, the iron catalyst is one or more of dicyclopentadienyl iron, ferrous chloride, ferrous acetylacetone, and ferrous titanate.
[0015] As one embodiment of the present invention, the nickel catalyst is one or more of nickel acetylacetonate, dicyclopentadienyl nickel, and nickel dichloride.
[0016] In one embodiment of the present invention, the modifying component is one or more of methyl silicone resin, phenyl silicone resin, methylphenyl silicone resin, and MQ silicone resin. Organosilicon resins are a class of resins with silicon atoms as the main chain atom, possessing good processability, temperature resistance, and dielectric properties, but are rarely used as modifying components. The present invention uses methyl silicone resin, phenyl silicone resin, methylphenyl silicone resin, and / or MQ silicone resin as catalytic / modifying components introduced into the system. Firstly, their end-capping groups can assist in catalyzing the curing process of cyanate esters; secondly, they can improve resin toughness, while also considering temperature resistance and dielectric properties, resulting in a good modifying effect. The modifying component of the present invention must contain the main structural unit: However, it does not contain Si-OC units, such as structural units. .
[0017] This invention also provides a method for preparing a medium-temperature curing low-dielectric cyanate ester resin system; the method includes the following steps: S1. Heat the curing agent to 40℃-100℃, add the catalyst, stir and mix evenly, and then cool to room temperature for later use. S2. Heat the cyanate ester resin matrix to 100℃-120℃, add the modified components in batches, stir evenly, and then cool down to 80℃-100℃. S3. Under stirring conditions, add the mixture of curing agent and catalyst, and continue stirring to mix evenly to obtain the cyanate ester resin system.
[0018] In one embodiment of the present invention, in step S1, the stirring rate is 1000-1500 r / min and the stirring time is 10-20 min.
[0019] In one embodiment of the present invention, in step S2, the stirring rate is 2000-2500 r / min and the stirring time is 15-20 min.
[0020] In one embodiment of the present invention, in step S3, the stirring rate is 2000-2500 r / min, and stirring continues for 5-10 min.
[0021] Compared with the prior art, the present invention has the following beneficial effects: 1) The cyanate ester resin matrix of the present invention is preferably a low dielectric system with high purity, minimal impact from impurities, and can ensure superior dielectric properties. 2) The curing agent and catalyst of the present invention are a compound system with a small overall dosage, which will not affect the dielectric properties of the resin system; the curing agent and catalyst have good dispersibility in the resin and can be cured at medium temperature, and can maintain a high reaction rate during post-curing, saving energy and improving efficiency. 3) The preparation method of the present invention is simple to operate, has a long process window, a controllable curing process, a short curing time, low residual stress in the cured resin, and the system is solvent-free, making it easy to scale up production. It is suitable for various processes such as liquid molding and prepreg, and is helpful for the application of related products in the fields of transportation and space. Detailed Implementation
[0022] The present invention will be described in detail below with reference to embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several adjustments and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.
[0023] Example 1 This embodiment relates to a medium-temperature curing low-dielectric cyanate ester resin and its preparation method, the preparation process of which includes the following steps: (1) Take 5g of nonylphenol and stir at 40℃, add 0.04g of 2-ethylhexanoate, stir at 2500r / min for 10min, stir evenly and then cool to room temperature for later use; (2) Take 95g of bisphenol E cyanate resin and add it to a three-necked flask. Gradually heat the flask to 120°C and slowly add 7g of the modified component methyl phenyl silicone resin in batches. Stir at 2500r / min for 20min. After stirring evenly, cool the flask to 100°C. (3) Under stirring conditions of 2500r / min, slowly add the mixed curing agent and catalyst into the system and continue stirring for 5-10min to make it evenly mixed, thus obtaining the cyanate ester resin system.
[0024] Example 2 This embodiment relates to a medium-temperature curing low-dielectric cyanate ester resin and its preparation method, the preparation process of which includes the following steps: (1) Take 3g of nonylphenol and stir at 40℃, add 0.06g of zinc 2-ethylhexanoate, stir at 2500r / min for 10min, stir evenly and then cool to room temperature for later use; (2) Take 97g of tetramethylbisphenol F cyanate resin and add it to a three-necked flask. Gradually heat the flask to 120°C and slowly add 15g of the modified component methylphenyl silicone resin in batches. Stir at 2500r / min for 20min. After stirring evenly, cool the flask to 100°C. (3) Under stirring conditions of 2500r / min, slowly add the mixed curing agent and catalyst into the system and continue stirring for 5-10min to make it evenly mixed, thus obtaining the cyanate ester resin system.
[0025] Example 3 This embodiment relates to a medium-temperature curing low-dielectric cyanate ester resin and its preparation method, the preparation process of which includes the following steps: (1) Take 3g of 6-ethyl-2-naphthol and stir at 100℃. Add 0.04g of ferrous acetylacetone and stir at 2500r / min for 10min. After stirring evenly, cool to room temperature for later use. (2) Take 72g of bisphenol E cyanate resin and 25g of bisphenol M cyanate resin and add them to a three-necked flask. Gradually raise the temperature to 110°C and slowly add 10g of the modified component MQ silicone resin in batches. Stir at 2500r / min for 20min. After stirring evenly, cool down to 100°C. (3) Under stirring conditions of 2500r / min, slowly add the mixed curing agent and catalyst into the system and continue stirring for 5-10min to make it evenly mixed, thus obtaining the cyanate ester resin system.
[0026] Example 4 This embodiment relates to a medium-temperature curing low-dielectric cyanate ester resin and its preparation method, the preparation process of which includes the following steps: (1) Take 2g of nonylphenol and stir at 40℃, add 0.03g of zinc 2-ethylhexanoate, stir at 2500r / min for 10min, stir evenly and then cool to room temperature for later use; (2) Take 98g of bisphenol M type cyanate resin and add it to a three-necked flask. Gradually heat the flask to 100℃ and slowly add 6g of the modified component methyl phenyl silicone resin in batches. Stir at 2500r / min for 20min. After stirring evenly, cool the flask to 80℃. (3) Under stirring conditions of 2500r / min, slowly add the mixed curing agent and catalyst into the system and continue stirring for 5-10min to make it evenly mixed, thus obtaining the cyanate ester resin system.
[0027] Comparative Example 1 This comparative example relates to a low-dielectric cyanate ester resin and its preparation method, the preparation process of which includes the following steps: (1) Take 5g of nonylphenol and stir at 40℃, add 0.04g of 2-ethylhexanoate, stir at 2500r / min for 10min, stir evenly and then cool to room temperature for later use; (2) Take 95g of bisphenol E cyanate resin and add it to a three-necked flask. Gradually heat the flask to 120°C and stir it at 2500r / min for 20min until it is completely melted. Then cool the flask to 100°C. (3) Under stirring conditions of 2500r / min, slowly add the mixed curing agent and catalyst into the system and continue stirring for 5-10min to make it evenly mixed, thus obtaining the cyanate ester resin system.
[0028] Comparative Example 2 This comparative example relates to a low-dielectric cyanate ester resin and its preparation method, the preparation process of which includes the following steps: (1) Take 2g of 1,3,5-benzenetriethanol and stir at 40℃, add 0.04g of 2-ethylhexanoate, stir at 2500r / min for 10min, stir evenly and then cool to room temperature for later use; (2) Take 98g of bisphenol M cyanate resin and add it to a three-necked flask. Gradually heat the flask to 120°C and stir it at 2500r / min for 20min until it is completely melted. Then cool the flask to 100°C. (3) Under stirring conditions of 2500r / min, slowly add the mixed curing agent and catalyst into the system and continue stirring for 5-10min to make it evenly mixed, thus obtaining the cyanate ester resin system.
[0029] Comparative Example 3 The basic structure is the same as in Example 2, except that the methyl phenyl silicone resin is replaced with epoxy-modified silicone resin SMH-60.
[0030] The performance tests of the above embodiments and comparative examples are shown in Table 1. The glass transition temperature test standard refers to GB / T 40396-2021, and the dielectric constant test standard refers to GB / T 5597-1999. Table 1
[0031] A comparison of Example 2 and Comparative Example 3 in Table 1 shows that replacing the epoxy-modified silicone resin increases the dielectric constant and significantly decreases the glass transition temperature. In the system of this invention, only those containing the main structural unit are selected. The silicone resin can balance temperature resistance and dielectric properties, and has a good modification effect.
[0032] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.
Claims
1. A medium-temperature curing low-dielectric cyanate ester resin system, characterized in that, The cyanate ester resin system comprises 95-99 parts by weight of a cyanate ester resin matrix, 1-5 parts by weight of a curing agent, 0.01-0.1 parts by weight of a catalyst, and 5-20 parts by weight of a modifying component; the modifying component contains structural units: Silicone resin.
2. The medium-temperature curing low-dielectric cyanate ester resin system according to claim 1, characterized in that, The modified component is one or more of methyl silicone resin, phenyl silicone resin, methylphenyl silicone resin, and MQ silicone resin.
3. The medium-temperature curing low-dielectric cyanate ester resin system according to claim 1, characterized in that, The cyanate resin matrix is selected from one or a mixture of several of bisphenol A cyanate, bisphenol E cyanate, bisphenol M cyanate, and tetramethylbisphenol F cyanate.
4. The medium-temperature curing low-dielectric cyanate ester resin system according to claim 1, characterized in that, The curing agent is an alkyl-substituted phenol.
5. The medium-temperature curing low-dielectric cyanate ester resin system according to claim 4, characterized in that, The alkyl-substituted phenol is selected from one or more of nonylphenol, 6-ethyl-2-naphthol, guaiacol, cashew phenol, and diallyl bisphenol A.
6. The medium-temperature curing low-dielectric cyanate ester resin system according to claim 1, characterized in that, The catalyst is one or more of the following: tin catalyst, zinc catalyst, iron catalyst, and nickel catalyst.
7. The medium-temperature curing low-dielectric cyanate ester resin system according to claim 6, characterized in that, The tin catalyst is one or more of dibutyltin dilaurate, tin 2-ethylhexanoate, and dioctyltin oxide; The zinc catalyst is one or more of zinc acetylacetonate, zinc octanoate, zinc isooctanoate, zinc 2-ethylhexanoate, and zinc chloride. The iron catalyst is one or more of dicyclopentadienyl iron, ferric chloride, ferrous acetylacetone, and ferrous titanate. The nickel catalyst is one or more of nickel acetylacetonate, dicyclopentadienyl nickel, and nickel dichloride.
8. A method for preparing a medium-temperature curing low-dielectric cyanate ester resin system according to any one of claims 1-7, characterized in that, The method includes the following steps: S1. Heat the curing agent to 40℃-100℃, add the catalyst, stir and mix evenly, and then cool to room temperature for later use. S2. Heat the cyanate ester resin matrix to 100℃-120℃, add the modified components in batches, stir evenly, and then cool down to 80℃-100℃. S3. Under stirring conditions, add the mixture of curing agent and catalyst, and continue stirring to mix evenly to obtain the cyanate ester resin system.
9. The method for preparing the medium-temperature curing low-dielectric cyanate ester resin system according to claim 8, characterized in that, In step S1, the stirring rate is 1000-1500 r / min and the stirring time is 10-20 min.
10. The method for preparing the medium-temperature curing low-dielectric cyanate ester resin system according to claim 8, characterized in that, In step S2, the stirring rate is 2000-2500 r / min and the stirring time is 15-20 min; in step S3, the stirring rate is 2000-2500 r / min and stirring continues for 5-10 min.